USDT is not a scam. It is currently the largest and most widely used stablecoin by market cap, pegged to 1 USD, issued by Tether, and commonly used for trading pricing and fiat-to-crypto transfers.
However, it is not risk-free: its reserve transparency is average, and during extreme market conditions it has briefly dropped below 1 USD (though it quickly regained its peg). For everyday use, USDT is perfectly fine for beginners. For large amounts, consider diversifying into USDC, which has higher regulatory compliance. For the differences between the two, see What is a Stablecoin.
⚠️ The real risk often comes from selecting the wrong network for transfers (TRC20/ERC20/BEP20). See How to Transfer USDT, and always test with a small amount first.